Question

Which is a connecting link between fishes and amphibians?

• A. Catfish
• B. Gambusia
• C. Protopterus
• D. Clupea

Answer 1

The correct option is C Protopterus

The African lungfishes are the genus Protopterus and constitute the four species of lungfish found in Africa. Protopterus is the sole genus in the family Protopteridae.

The African lungfish is an example of how the evolutionary transition from breathing water to breathing air can happen. Lungfish are periodically exposed to water with low oxygen content or situations in which their aquatic environment dries up. Their adaptation for dealing with these conditions is an outpocketing of the gut, related to the swim bladder of other fishes, that serves as a lung.

The lung contains many thin-walled blood vessels, so blood flowing through those vessels can pick up oxygen from air gulped into the lung.

The African lungfishes are obligate air breathers, with reduced gills in the adults. They have two anterior gill arches that retain gills, though they are too small to function as the sole respiratory apparatus.